Argument Passing

Here is what I have come up with (which is working for me). I would like someone to verify that the regular expresion does ONLY what I want.

function _insert_block_substitute_tags($text) {
  if (preg_match_all("/\[block:([^=\\]]+)=?([^=\\]]*)? args:?([^\\]]*)?\]/i", $text, $match)) {

    foreach ($match[3] as $key => $value) {
      $raw_tags[] = $match[0][$key];
      $module = $match[1][$key];
      $delta = $match[2][$key];
      $args = $match[3][$key];

      if ($args != NULL) {
        $args = explode(',', $args);
      }
      else {
        $args = array();
      }

      $block = module_invoke($module, 'block', 'view', $delta, $args);

      $repl[] = theme('insert_block_block', $block);
    }
    return str_replace($raw_tags, $repl, $text);
    //return print_r($match); //TESTING
  }
  return $text;
}

[block:MODULE=DELTA args:ARG1,ARG2,...,ARGN]